Combined door check and burglar alarm



Sept. [1, 1923.

' w. 'r. FAIRALL COMBINED DOOR CHECK AND BURGLAR ALARM Fi led May 51. 1922 IN VEN TOR. War Imam BYQ ATTORNEY Patented Sept. 11, 1923.

WALTER T. FAIRALL, OF'STOCKTONyCALIFORNIA.

COMBINED DOOR CHECK BURGLAR ALARM.

Application filed I??? 81 To all whom it may concern: I

Be it known that I, VVALTER T. FAIRALL, a citizen of the United States, residing at Stockton, county of San Joaquin, State of California,'have invented certain new and useful Improvements in Combined Door Checks and Burglar Alarms; andI do declare the following to be a full, clear, and exact description of the same, reference be ing had to the accompanying drawings, and to the characters of reference marked thereon, which forma part of this application.

This invention relates to an improved door check which may at the same time be used as an eilicient burglar alarm, the principal object of my invention being to provide a device'of this character which may be instantly applied to a door to merely serve as a check against undesiredjopening of the same; and which may in addition have a blank cartridge inserted therein which'will be exploded when anyforcing openof the "door is attempted, so that the device will then serve not only to prevent opening of the door, but also as an'eife'ctive burglar alarm, which by arousing the occupant oi' the room, will be a valuable aid in catching the prospective intruder before he can make good his escape.

Anotherfobject is to provide a device of this character which is absolutely harmless to handle, sin'cefI have designed and arranged the operating parts in such a'manner that the trigger member which explodes the cartridge is never cocked until an actual attempt to open the door is made.

I have also made 'thedevice so that while strong and efficient, it is very light and small, and may easily be carried in a hand bag or suitcase, either as a single unit, or as two separated parts. In the latter case, the cartridge maybe left inserted-in place, without the slightest danger that 'itwill be accidentally exploded with jolting or disturbance of any kind, as when the owner rum- 1 mages through hisbag for other articles.

The device is therefore admirably suited not only for home use, being easily and quickly applied toa door byfman,'woman or child, but for use by persons travelling, and

' who are forced to stop over night at hotels ,1922. Serial- No. 564,801.

that'he and his property aresafe from unwelcome intrusion In the morning 'the device can be again removed and packed away without disturbing or removing the cartridge, if this has not been discharged during the night. i

The device may also be made asa permanent attachment to adoor.

These objects I accomplish by means of such structure and relative arrangement of ,parts as will fully appear by a perusal of the following specificatlon and claims.

In the drawings similar characters of'reference indicate corresponding parts in the several views. 7

l is-a perspective'view of thede viceas applied to a door. 1

Fig.9 is'a longitudinal section of'the device det ched with the,parts in their normal; positions.

Fig. 3 is a similar view showing the parts telescoped or moved together and the cartrid'ge exploded.

Fig. 4 is a side view of the device when arranged to serve as a permanent attachment. "Referring now more particularly to the characters of reference on the drawings, the numeral l denotes a tube having fixed on one end a preferably forked prong member"2 adapted to engage a floor. Slidably mounted in said tube beyond the prong is a'h'ammer or plunger '3 connected by means of 'a compression spring 4: to another tube 5 slidably'mounted in that end-0f the tube 1 opposite to the pronged end, said tube 5 "being provided 'on its outer end with a prong member 6 similar to the member '2 andadapted to engage a. door.

Intermediate the prong 2 and hammer 3 is a chamber 7 for a blank cartridge 8, the latter being insertable through a slot 9 provided'in the tube 1 adjacent the block 7.

v The-hammer is normally held from movement toward the cartridge,- regardless of the compression of the spring 4, by' means of a catch 10 engaging the hammer and formed as part of a flat spring '11 mounted onto the tube 1* and partly projecting-into a slot 12 cutin said tube.

Beyond the hammer, and toward the tube 5, the spring 12 is providedwitha cam surface 13 projecting into the tube 1 into the plane'of the tube 55, said surface being en- ;gaged-by-the inner end of the tube 5when thelatter'is moved 'totelescope into the tube 1- a predetermined 5 distance, during 5 which movement the spring 4 is being compressed. The engagement of the surface 13 of the spring 11 by the tube 5 causes the free portion of said spring to be moved outwardly of the tube 1, which withdraws the catch I suflicient to so engage the spring-cam, further telescopic movement of said tube is prevented by means of a collar 14: thereon which engages the outer end of the tube 1.

To apply the device to a door, the tubes 1 and 5 are telescoped just enough to place the spring 4: under compression somewhat, and the prongs 2 and 6 engaged with the floor and door at a suitable angle, as shown in Fig. 1.

The door may then be opened slightly, until such opening movement has caused the tubes to telescope one with theother to a point where the collar 14 will engage the tube 1 and prevent further telescopic movement, as previously described. At the same time, a cartridge, if present, will be exploded, but whether the cartridge is used or not, the door cannot be then opened further, any more pressure exerted on the latter merely tending to bury the prongs deeper into the surfaces with which they are engaged.

It will be noted that until the two tubes are telescoped about to their limit, the hammer remains inactive, and cannot possibly accidentally move to explode the cartridge.

The tube 5, with the hammer and spring 4, form a complete unit independent of the tube 1, and may be withdrawn from the latter at will if this is desired.

In Fig. 4 I have shown a means whereby the device may be permanently attached to a door, for use in office buildings and the like. In this type of device, the door prong 6 is replaced by a bracket 15 attached to the door a suitable distance from the floor, the tube 5 being pivoted therein. lVhen not in use, the device stands vertically and is held in such position by a ring 16 on the door,

which may he slipped from over the upper end of the device at will.

From the foregoing description it will be readily seen that I have produced such a.

device as substantially fulfills the objects of the invention as set forthherein.

, While this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention, as defined by the appended claims, I,

1 Having thus described my invention, what I claim as new and useful and desire to secure by Letters Patent, is

1. A combined-door check and burglar alarm comprising a pair of tubes slidably mounted together for telescopic movement, a cartridge chamber in one of said tubes, a hammer adapted to move toward said chamber, a normally slack compression spring between the hammer and the inner one of the tubes, and mean-s whereby when the tubes are telescoped together the spring will be compressed without any movement being imparted to the hammer until said tubes have been so telescoped to a predetermined extent.

2. A combined door check and burglar alarm comprising a pair of tubes slidably -mounted together for telescopic movement, a

tomatically engaging the hammer to hold the same from movement toward the barrel, and a cam member projecting from the catch member into the path of movement of the 1nner one of the tubes and adapted to be engaged by the latter to cause the catch to be released from the hammer .when said tube has moved toward the hammer a predetermined distance.

7 3. A combined door check and burglar alarm comprising 'a pair'of tubes slidably mounted together for telescopic movement, a cartridge chamber in one of said tubes, a hammer adapted to move toward said chamber, a normally slack compression spring between the hammer and the inner one of the tubes, a catch member normally and automatically engaging the hammer to hold the same from movement toward the barrel, a member formed with the catch member and adapted to be engaged by the 1nner one of the tubes after the latter has ,moved a certain distance, and means whereby such engagement will cause the catch to be disengaged from the hammer, whereby the latter is then free to move toward the barrel.-

4. A combined door check and burglar alarm comprising'an outer tube having a cartridge chamber adjacent one end, a catch member mounted on and projecting into said tube intermediate its ends, an independent tube slidable into the outer tube from the end thereof opposite the cartridge chamber,

a hammer likewise slidable in said outer tube, spring means between the hammer and inner tube, said hammer abutting against the catch after the inner tube has been inserted a predetermined distance into the outer tube, means actuated by a further inward movementof said inner tube for releasing the catch from the hammer.

5. A combined door check and burglar alarm comprising an outer tube having a cartridge chamber adjacent one end, a catch member mounted on and projecting into said tube intermediate its ends, an independent tube slidable into the outer tube from the end thereof opposite the cartridge chamber, a hammer likewise slidable in said outer tube, spring means between the hammer and the inner tube, said hammer abutting against the catch after the inner tube has been inserted a predetermined distance into the outer tube, and a cam formed with said catch member and projecting into the path of telescopic movement of the inner tube, the hammer being seated between the catch and cam. 6. A combined door check and burglar alarm comprising an outer tube having a ner tube, said hammer abutting against the catch after the inner tube has been inserted into the outer tube for a predetermined distance, and a common means normally resisting withdrawal of the hammer when once seated against the catch and for causing the catch to be moved clear of the hammer by the continued inward movement of the inner tube a predetermined distance.

In testimony whereof I aflix my signature, I

WALTER T. FAIRALL. 

